Impact of spectral broadening on plasmonic enhancement with metallic gratings

摘要

The Purcell factor (PF) of the propagating surface plasmon polariton (SPP) mode on metallic grating is evaluated with full integration formula of Fermi's golden rule, while both spontaneous emission linewidth of single quantum dot and the spectrum broadening of photonic density of state (DOS) due to the propagation loss of SPP mode are involved. It is found that the PF would be degraded by taking account of the emission linewidth. For emitters with narrow linewidth, the DOS broadening is dominant while it would be helpful to some degree for wide-linewidth emitters.